Delegate declaration and instantiation in C Sharp (C#) - Mini Project: Build & Apply

Delegate declaration and instantiation

📖 Scenario: You are creating a simple program to greet people using different greeting styles. You will use a delegate to hold references to greeting methods.

🎯 Goal: Build a program that declares a delegate, creates a delegate instance pointing to a greeting method, and calls it to display a greeting message.

📋 What You'll Learn

Declare a delegate type named GreetDelegate that takes a string parameter and returns void.

Create a method named SayHello that takes a string parameter and prints a greeting message.

Instantiate a GreetDelegate delegate named greet pointing to the SayHello method.

Invoke the greet delegate with the name "Alice".

Print the greeting message to the console.

💡 Why This Matters

🌍 Real World

Delegates are used in event handling, callbacks, and designing flexible APIs where methods can be passed around as variables.

💼 Career

Understanding delegates is essential for C# developers working with GUI applications, asynchronous programming, and frameworks like .NET.

1

Declare the delegate type

Declare a delegate named GreetDelegate that takes a string parameter and returns void.

C Sharp (C#)

// Declare the delegate type here
// Your code here

Need a hint?

A delegate declaration starts with the keyword delegate, followed by the return type, delegate name, and parameter list.

2

Create the greeting method

Create a method named SayHello that takes a string parameter called name and prints "Hello, {name}!" to the console.

C Sharp (C#)

public delegate void GreetDelegate(string name);

// Create the SayHello method here
// Your code here

Need a hint?

Use System.Console.WriteLine with an interpolated string to print the greeting.

3

Instantiate the delegate

Inside the Program class, create a GreetDelegate variable named greet and assign it to the SayHello method.

C Sharp (C#)

public delegate void GreetDelegate(string name);

public class Program
{
    public static void SayHello(string name)
    {
        System.Console.WriteLine($"Hello, {name}!");
    }

    // Instantiate the delegate here
    // Your code here
}

Need a hint?

Assign the method name SayHello directly to the delegate variable.

4

Call the delegate and print the greeting

In the Main method, call the greet delegate with the argument "Alice" to print the greeting message.

C Sharp (C#)

public delegate void GreetDelegate(string name);

public class Program
{
    public static void SayHello(string name)
    {
        System.Console.WriteLine($"Hello, {name}!");
    }

    public static void Main()
    {
        GreetDelegate greet = SayHello;
        // Call the delegate with "Alice" here
        // Your code here
    }
}

Need a hint?

Invoke the delegate like a method with the string argument.